section.21.(qcs.electrical)

8/17/2019 Section.21.(QCS.electrical)

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QCS 2007 Section 21 Part 1 General Provisions for Electrical Page 1Installation

Qatar General Organization for Standards and Metrology

QCS 2007, 3

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1. GENERAL PROVISIONS FOR ELECTRICAL INSTALLATION.....................2

1.1.1 Scope 2 1.1.2 Regulations 2 1.1.3 Existing Services 3 1.1.4 Contract Drawings 3

1.1.5 Shop Drawings 3 1.1.6 Progress Drawings 5 1.1.7 As built drawings 5 1.1.8 Builders Work 5 1.1.9 Programme 5 1.1.10 Equipment and Materials Approval 6 1.1.11 Fire and Safety Precautions 6 1.1.12 Protection 7 1.1.13 Quality of Staff/Personnel 7 1.1.14 Climatic Conditions 8 1.1.15 Samples 8 1.1.16 Quality of Materials 9

1.1.17 Equipment Duties and Ratings 9 1.1.18 Workmanship 9 1.1.19 Labels/Circuit Lists/Cable Identification 10 1.1.20 Segregation of Services 11 1.1.21 Electricity Supply 12 1.1.22 Polarity 12 1.1.23 Safety Interlocks 13 1.1.24 Spare Parts 13 1.1.25 Protection of Excavation 14 1.1.26 Supply of materials 14 1.1.27 Special Requirements 15


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1. GENERAL PROVISIONS FOR ELECTRICAL INSTALLATION

1.1.1 Scope

1 The Electrical Installation Contractor, herein referred to as the 'Contractor' within this part andall other Section 21 parts of this specifications shall carry out all electrical works complete in

accordance with the requirements of the Project Documentation.

2 The scope of work shall include but not be limited to:

(a) the supply and installation of all services, equipment, components, accessories andfittings required for the operation of the facility to the extent specified and detailed onthe Drawings and Specifications including 400 days maintenance after provisionalhandover

(b) builder's work in connection with the Electrical Installations, including supply,necessary inserts and sleeves

(c) any work which can be reasonably inferred as necessary for the safe, satisfactoryoperation of each system, whether such work is specified or shown on drawings ornot

(d) the supply and installation of cables, conduits, boxes and termination points, for themotors, starters, controls and the like for the Process Equipment, Heating, Ventilation

and Air-conditioning and Plumbing services(e) arranging for installation of permanent Electrical supply by the Qatar General Electricity

and Water Corporation (QGEWC), including submission of all necessary documents tothe QGEWC, and carrying all necessary approvals and obtaining consumption meters

(f) attending upon the Supply Authority installing mains power supply and carrying outprimary and secondary injection tests

(g) arranging and carrying out all necessary approvals with Q-TEL for the TelephoneSystem

(h) arranging and carrying out all necessary approvals with the Qatar Civil DefenceDepartment for the Fire Alarm System, extinguishing and protection systems.

1.1.2 Regulations

1 All supplies and services offered in response to this specification shall conform to the latest

standards.

2 The design, equipment and installation requirements shall comply with the standards andrecommendations laid down by the following :

(a) Regulations for Electrical Installations as issued by the Qatar General Electricity and Water Corporation (QGEWC) Qatar

(b) Regulations for Electrical Installations as issued by the Institution of ElectricalEngineers (I.E.E.), London (for points not included in QGEWC Regulations)

(c) Recommendations for Lighting Installations as issued by QGEWC and the CharteredInstitute of Building Services, London

(d) Standards relating to Electrical Installations and equipment as issued byInternational Electrotechnical Commission (I.E.C.) and British Standards Institute(BSI)

(e) Regulations for telephone system installation as issued by Q-TEL

(f) National Electrical Code issued by National Fire Protection Association (NFPA),Boston, U.S.A

(g) Rules of the Qatar Civil Defence Department for Fire Alarm Installations.

3 Where two or more applicable standards and/or the Specifications are in conflict, the moststringent shall apply.


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1.1.3 Existing Services

1 The contractor is deemed to have visited and inspected the site to familiarise himself with theexisting site conditions and services at tender stage.

2 The contractor shall obtain the existing services record drawings from QGEWC and variousutility services departments (i.e. Q-TEL, CDD etc).

3 Co-ordination between shop drawings, work on site and existing services shall be carried outby the Contractor.

4 The Contractor shall be fully responsible for any damages to the existing services includingrepairs, and penalties imposed by the concerned parties etc and for removing any siteobstacles such as underground cables, pipes, civil works etc. which is obstructing his workon site.

5 The Contractor shall also be responsible for liaison with QGEWC, Q-TEL and all othergovernment utility departments to disconnect or divert the existing services supply to theexisting site prior to demolishing.

1.1.4 Contract Drawings

1 The indication and/or description of any item on the Drawings or in the Specification, unlessotherwise specifically stated, implies an instruction to supply and fix such items.

2 Notes on Drawings referring to individual items of work take precedence over theSpecification.

3 Drawings show the general run of cables, raceways, etc. and the approximate location ofequipment and utilities; symbols and schematic diagrams are of no dimensional significance.Obtain from the Engineer dimensions not shown on, or which cannot be determined fromDrawings. Do not scale drawings to obtain locations.

4 Notify the Engineer of conflicting requirements. Where departures from the drawings aredeemed necessary, details of such departure and reasons thereupon shall be submitted to

the Engineer for approval.

5 No such departure shall be made without prior written approval of the Engineer.

1.1.5 Shop Drawings

1 The term 'shop drawings' includes fabrication, erection, layout and setting out drawings;manufacturer's standard drawings, schedules; descriptive literature, illustrations, cataloguesand brochures; performance and test data; wiring and control diagrams and other drawingsand descriptive data pertaining to materials, equipment, raceway systems, control systemsand methods of construction as required to show that materials, equipment and systems andposition thereof, conform to the Contract Documents. The term 'manufactured' applies tostandard units usually mass produced. The term 'fabricated' means items specificallyassembled or made out of selected materials to meet individual design requirements.

2 Shop drawings shall establish actual detail of all manufactured or fabricated items, indicateproper relation to adjoining work, amplify design details of electrical equipment in properrelation to physical spaces in the structure, and incorporate minor changes of design orconstruction to suit actual conditions.

3 The Contractor shall submit for approval, and obtain in due time to conform to the ContractProgram, all shop and installation drawings based on the design drawings approved by theQGEWC and all other relevant Municipality and Government Authorities.


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4 The Contractor, immediately after being awarded the said Contract, shall prepare and submitshop drawings. Shop drawings shall be submitted with such promptness as to cause no delayin his own work nor to any other Contractor. No extensions of time will be granted because offailure to have shop drawings submitted in ample time to allow for processing, in accordancewith the submittals schedule outlined in Section 9, Part 1, Clause 1.1.4.

5 Provide shop drawings, to a scale not smaller than the corresponding layout drawings,showing the following and obtain approval before commencing work:

(a) exact runs and sizes of conduits, ducts, cables, cable trays and trunking(b) layout drawings for each separate electrical installation showing the actual locations

of points, suitably identified, the locations of switchgears, switchboards, motor controlcentres and distribution boards, details and types of fittings

(c) plans showing the equipment assembly, space requirements, clearances andlocations for cable entrances and anchor bolts

(d) elevations showing all parts, devices, components and nameplates, positions andarrangements of the equipment. Show as many elevations as necessary to clearlydepict component and device arrangements

(e) schedules of points, indicating how the various outlets are connected to thedistribution boards, size of circuit wiring, the rating of the protective device and thetype and size of appliance of fitting

(f) schematic diagram of connections of distribution boards, and equipment to main

switchboards showing sizes of feeders, etc(g) schematic and elementary wiring diagrams, of each unit of each equipment, showing

numbered terminal points, numbered wires and numbered interconnections to otherequipment and remote devices

(h) connection wiring diagrams, of each unit of each equipment, showing numberedterminal points, numbered wires and numbered interconnections to other equipmentand remote devices

(i) complete catalogue information of all parts and components of electrical equipment(j) all cable routings and layouts for the different electrical services, feeders and branch

circuits showing routes, sizes and types of cables(k) any other data necessary for the proper maintenance of the installations.

6 Drawings shall be ISO standard size A1. Lettering shall be stencilled. Shop drawings andsamples shall be properly identified with the name of the Project, the Contractor, the Sub-

Contractor and the date, and signed by Contractors Authorised Engineers.

7 Final co-ordination of electrical works with mechanical, structural and architectural work shallbe carried out from complete shop drawings and sufficient time shall be allowed for co-ordination and checking of shop drawings and calculations after shop drawings aresubmitted.

8 Individual shop drawings shall be submitted following the distribution of the co-ordinationdrawings and shall bear a stamp indicating that the work has been co-ordinated with othertrades.

9 The Engineer's review and approval of shop drawings submitted by and approved by theContractor is for general conformance with the design concept and information given in theContract Documents and shall not relieve the Contractor from responsibility for any deviationsfrom the requirements of the Contract Documents. The Engineer's review and approval shallnot be construed as a complete check nor shall it relieve the Contractor from responsibility forerror of any sort in shop drawings or schedules, or from the necessity of furnishing any workrequired by the Contract Documents which may have been omitted on the shop drawings.The Engineer's review and approval of a component item shall not indicate review andapproval of the complete assembly in which it functions.

10 The Engineer or the supervising consultant shall forward electrical drawings andspecifications which are to be submitted for approval to QGEWC, when appropriate.However, it shall be the Contractors responsibility to obtain written approval from QGEWC forall such drawings and specifications appertaining to the work carried out under the contract.


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QGEWC approvals may take a considerable time to obtain and the contractor should makeallowance for this and be available for liaising with and pursuing approvals with QGEWC.

1.1.6 Progress Drawings

1 Provide and keep on the job at all times, one complete and separate set of blackline prints ofthe electrical work on which shall be clearly, neatly and accurately noted, promptly as the

work progresses, all architectural and electrical changes, revisions and additions to the work.Whatever work is installed otherwise than as shown on the Contract Drawings, such changesshall be noted.

2 Indicate daily progress on these prints by colouring in the various conduit, ducts, trunking,cable trays, fixtures, apparatus and associated installation works erected.

1.1.7 As built drawings

1 The contractor shall provide the as built drawings, as approved by the engineers, in DXFformat or AutoCAD DWG format, either in floppy diskettes or in CD-ROM, as per the ProjectDocumentation requirement. The drawings shall be submitted not later than 2 months aftercompletion of the Project, or putting into operation, whichever is earlier. An addition, 3 sets ofhard copy of all relevant drawings, which will be required for operation and maintenance,

shall be supplied in bound book forms immediately after the commissioning of the Project.The quality of these drawings shall be consistent with the standard of QGEWC. Diary sheetsfor Work completed shall not be authorised until such records have been presented to the Engineer and accepted.

2 The contractor shall supply, 3 sets of all operation and maintenance manuals in original, fromthe manufacturer in bound book forms, at least 2 weeks prior to commissioning of theequipment. These shall also be supplied, in computer diskettes, based on popular Microsoftwindow based publishing software programmes, along with the as built drawings asmentioned above, as specified in the Project Documentation.

1.1.8 Builders Work

1 Lay electrical works in advance of pouring concrete slabs and construction of walls. ObtainEngineer's approval before commencing builder's work in connection with electricalinstallation. Related co-ordinated shop-drawings shall be submitted for approval as per therelated clause 1.1.5 of this section. Materials approval shall be obtained as per proceduredetailed in clause 1.1.9 below. The contractor shall make it certain that drawings properly co-ordinated with other works are submitted immediately after signing of the contract andapproval of drawings and the materials are obtained at least one month prior to thecommencement date of the construction.

2 Check with other trades to ensure equipment and material can be installed in space provided.

3 Provide other trades with information necessary for them to execute their work.

4 Details on drawings which are specific regarding dimensions and locations, are forinformation purposes. Co-ordinate with other trades to ensure work can be installed asindicated.

1.1.9 Programme

1 The Contractor shall produce a work programme based on CPM or Bar-chart form indicatingthe time required for various operations to complete the Project in time. The following pointsshall be highlighted in the programme:

(a) mobilisation(b) drawings/submittals(c) approvals


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(d) equipment deliveries including delivery periods from supply sources external to theState of Qatar

(e) first fix(f) cabling(g) main/sub-main distribution equipment(h) second fix(i) fixing of light fittings(j) testing(k) commissioning and handing over.

2 The Contractor is responsible for all liaison with QGEWC in respect of programming theinstallation and commissioning of complete electrical system. The Contractor shall ensurethat QGEWC are at all times kept informed of the current progress of the electrical works onsite and that his approved electricity supply subcontractor programs the cable laying works inthe specified sequence in accordance with the approved programme.

1.1.10 Equipment and Materials Approval

1 Approval of materials and equipment shall be based on latest manufacturer's published data.

2 Complete and detailed information of all materials and equipment to be incorporated in the

work shall be submitted. Submit detailed description and specifications, catalogues cuts,installation data, diagrams, dimensions, controls and any other data required to demonstratecompliance with the Contract Documents. Each item submitted shall be referenced to theapplicable paragraph in the Specification.

3 At the request of the Engineer, submit a sample of any equipment or material for furtherstudy before approval. Where samples are required by the Engineer, the period required toobtain the sample will be taken into account when scheduling approvals.

4 Only approved materials shall be employed at the site. All materials installed which are notapproved shall be removed and reinstated by approved ones.

5 Time periods for equipment and materials approvals shall be as outlined in Section 9, Part 1,Clause 1.1.4.

1.1.11 Fire and Safety Precautions

1 Establish from Architectural Drawings where fire and smoke barriers exist, and makeadequate provision of fire and smoke barriers in and around trunking, conduits, cables, etc.,where they pass through floors and fire rated walls, and where protection systems areinstalled pack space between wiring and sleeve full with Fire Retardant Material and seal withcaulking.

2 The Contractor shall ensure that this work is carried out such that the integrity of any such firebarrier is properly maintained where pierced by electrical services.

3 For each switchboard the Contractor shall supply the following equipment:

(a) 1 no. electrical grade rubber mat to BS 921 1000 mm wide extending the full length ofthe switchboard

(b) 1 no. pair of electrical grade rubber gloves to BS 697. The hand glove should have thedate of test stamped on it.

(c) 1 no. notice in English and Arabic advising treatment for a person suffering fromelectrical shock.

4 The contractor shall put the notice for electrical shock treatment in details with sketches andinstructions as per standard procedures. The notice shall comply with the requirement of theQGEWC in content and format. However, this should include the following as a minimum,


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ACT IMMEDIATELY

(i) Safeguard Yourself

(ii) Switch off current or break electric circuit

(iii) Use or stand on some dry non-conducting material to remove the CASUALTYfrom cable or source of electricity.

(iv) Start artificial respiration and call for Medical AidTREATMENT FOR ELECTRIC SHOCK

ARTIFICIAL RESPIRATION

(KISS OF LIFE, MOUTH TO MOUTH METHOD)

(v) Lay the casualty on back and if possible on a table

(vi) Kneel or stand near to the casualty’s head

(vii) Remove any obstruction from the mouth

(viii) Support the nape of the neck and press top of the head so that it is tiltedbackwards

(ix) Open your mouth and take a deep breath, pinch the casualty’s nostrils with

your fingers. Seal your lips round his mouth and blow into his lungs until thechest rises.

(x) Remove your mouth and watch the chest falls

(xi) Repeat and continue inflation at your natural rate of breathing. Continue togive artificial respiration until natural breathing is restored or until the medicalaid arrives

(xii) When the casualty is breathing, place in recovery position, lying and resting onthe side. Remain with and watch casualty closely.

1.1.12 Protection

1 The Contractor shall be responsible for his work and equipment until finally inspected, testedand accepted. Materials and equipment which are not immediately installed after delivery to

site shall be stored carefully. Close open ends of work with temporary covers or plugs duringconstruction to prevent entry of obstructing material.

2 Protect work and material of other trades from damage that might be caused by his work orworkmen and make good damage thus caused.

3 Protect exposed live equipment during construction for personnel safety.

4 Shield and mark live parts "LIVE 240 VOLTS" or with appropriate voltage in English and Arabic.

5 Arrange for installation of temporary doors for room containing electrical distributionequipment. Keep these doors locked except when under direct supervision of an electrician.

1.1.13 Quality of Staff/Personnel

1 The electrical services installation shall be carried out in a professional manner byexperienced and qualified personnel.

2 Electrical contractor shall be to the classifications required by QGEWC and shall carry a validlicence.

3 Prior to the commencement of works the Contractor shall notify the Engineer of his intendedsite staffing levels.


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4 The Contractor shall appoint one graduate Electrical Engineer full time with 5 yearsexperience in similar works and qualified staff/personnel for the supervision of the ElectricalInstallation Works.

5 The name, qualifications and experience of the nominated engineers shall be submitted tothe engineer for approval within 15 days of the receipt of the order to commence the works.

6

An Electrical Foreman of 10 years experience in similar projects should be full time availableon site for direct follow up and implementation of the electrical works.

7 Qualified and Experienced Electricians shall be available on site to carry out the works inaccordance with the programme.

8 The Engineer reserves the right to require the Contractor to provide information anddocumentation as may be necessary to establish the validity of any individual personsproficiency and effect their removal from site should they prove to be unsatisfactory.

1.1.14 Climatic Conditions

1 The climate in Qatar in the summer months is hot and humid and a humidity of 100 % at30 °C has been recorded.

(a) violent sand and dust storms of several hours duration occur and even oncomparatively still days, fine dust is carried in suspension in the atmosphere.

(b) all apparatus and equipment shall, therefore, be so designed and constructed thatthey operate satisfactorily and without any deleterious effect for prolonged andcontinuous periods in the conditions stated above and at the following ambienttemperature conditions:(i) maximum sun radiation temperature in summer - 84 °C(ii) maximum ambient temperature in summer - 52 °C

(iii) average max. ambient temperature in summer - 45 °C(iv) minimum ambient temperature in winter - 0 °C(v) the altitude of Qatar may be taken as sea level.

2 The temperatures quoted above make no allowance for heat generated from equipment itselfor from any other equipment in the vicinity

3 The capacity and ratings of all electrical equipment and materials given are, unless otherwiseindicated, for Qatar climatic conditions. Provide the basis of the derating factors applied ineach case

4 Where specific sizes are indicated e.g. cable sizes, due allowances have been made in thedesign for the climatic conditions of Qatar and derating has been applied

5 Where no ratings or sizes are indicated for components and other accessories, supplyequipment which will give trouble free service in the ambient conditions stated above.

1.1.15 Samples

1 The term ‘samples’ includes natural materials, fabricated items, equipment, devices,

appliances, or parts thereof as specified and other samples as may be required to determinewhether kind, quality, construction, workmanship, finish, colour and other characteristics ofmaterials conform to requirements of the Contract Documents.

2 Samples shall establish kind, quality and other required characteristics of various parts of thework. Indicate details of construction, dimensions, capacities, weights and electricalperformance characteristic of equipment or material.

3 Samples and sample board should be prepared and identified by the manufacturer andstamped/engraved with make, type, Cat No. and size marking should be indelible and legible.


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1.1.16 Quality of Materials

1 Manufacturers shall provide their standard guarantees for products furnished under thisContract. However, such guarantees shall be in addition to and not in lieu of all other liabilitieswhich manufacturers and the Contractor may have by law or by other provisions of theContract Documents.

2

All materials, items of equipment and workmanship furnished under this Contract shall carrystandard warranty against all defects in materials and workmanship. Any faults due todefective or improper material, equipment, workmanship or Contractor's design whichdevelop shall be made good, forthwith, by and at the expense of the Contractor, including allother damage done to areas, materials and other systems resulting from this failure.

3 Guarantee that all elements of the systems are of sufficient capacity to meet the specifiedperformance requirements as set forth herein or as indicated.

4 Upon receipt of notice from the Engineer, of failure of any part of system or equipment duringthe period of maintenance, the affected parts shall be replaced.

1.1.17 Equipment Duties and Ratings

1 Power ratings shown for the proposed equipment are in accordance with the best informationavailable to the Engineer and are to be considered as minimum ratings. In the event

equipment items proposed by the Contractor should require motors with different powerrating than shown, it shall be the Contractor ’s responsibility to furnish circuit breaker, startingequipment, feeder and branch circuits, conduits, and accessories etc. as required to complywith the electrical code and prevent excessive voltage drop without added cost to the Client.

2 Where equipment to be furnished is installed in an existing enclosure or adjacent to existingequipment, the Contractor shall field check the dimensions of existing equipment, location ofconduits, etc., and shall familiarise himself with all existing conditions and difficulties to beencountered in performing such work.

3 Degree of protection for all electrical equipment shall be as follows:

IP 54, for indoor equipment

IP 55, for outdoor equipmentIP 68, for submersible equipment

4 All external equipment to be of metallic construction.

5 The equipment shall be located generally as indicated on the drawings and the contractorshall ensure that the equipment is suitably constructed to permit installation as shown. Theequipment shall where necessary be constructed in modular form to permit access into thebuildings and facilitate ease of erection at site.

6 The equipment arrangements and single line diagram are for guidance only and show apractical arrangement that would be acceptable. The contractor may propose an alternativearrangement which meets the requirements of the specification.

7 All equipment performing similar duties shall be of a single type and make and be fullyinterchangeable in order to limit the stock of spare parts required. This is to apply particularlyto such items as motors, switchgear, instruments, controls, relays, etc.

1.1.18 Workmanship

1 The entire work provided in this specification shall be constructed and finished in everyrespect in a workmanlike and substantial manner. The Contractor shall provide the system inaccordance with the best trade practice and to the satisfaction of the Engineer.


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2 Keep others fully informed as to the shape, size and position of all openings required forapparatus and give full information sufficiently in advance of the work so that all openingsmay be built in advance. Provide and install all sleeves, supports, etc., hereinafter specifiedor required.

3 Obtain detailed information from the manufacturers of apparatus as to the proper method ofinstalling and connecting same. Obtain all information from others which may be necessary tofacilitate work and the completion of the whole Project.

4 Provide the services of an experienced foreman, who shall be continuously in charge of theerection of the electrical work, together with all necessary skilled workmen, helpers andlabourers, required to properly unload, transfer, erect and connect up, adjust, start, operateand test the system.

5 Before installing any work, verify that it does not interfere with clearance required for otherwork. Notice of adverse conditions shall be forwarded in writing to the Engineer before anywork in question is installed. If notification is not made, and work installed causesinterference with the contemplated design, make such changes in his work as directed by theEngineer to permit the installation of all work of the Project, at no additional cost to the Client.

6 Raceways shall be run as straight and direct as possible in general forming right angles withor parallel with walls or piping and neatly spaced, with risers erected plumb and true, maintaina clearance of at least 25 mm between finished coverings and adjoining work. Approvedceiling height shall be obtained from Architectural Drawings.

7 All equipment and accessories shall operate without objectionable noise or vibration. Shouldoperation of any of the equipment or systems produce noise or vibration which is, in theopinion of the Engineer objectionable, make change in equipment and do all work necessaryto eliminate the objectionable noise or vibration at no additional cost to the Client.

8 Wherever possible services shall not cross expansion joints. Where this is unavoidable theservices shall accommodate the design movement without damage, by use of approvedexpansion couplings/flexible conduit arrangement.

9 All MV, HV and EHV works shall be carried out by a contractor or sub-contractor pre-qualif iedand approved by QGEWC. Proof of such approval shall be required in writing prior to theworks commencing on site and the name of any sub – contractor to be used shall be enteredin the relevant form of tender when the tender is submitted. All cable jointers to be used onthe Contract shall be required to undertake and pass a trade test conducted by QGEWC atthe Contractor ’s expense.

1.1.19 Labels/Circuit Lists/Cable Identification

1 For substations, switchgears, switchboards, motor control centres and panel boards:

(a) engraved lamacoid name plates, black with minimum 6 mm high white lettering.

2 For Distribution Boards and Circuit Breakers:

(a) where individually enclosed or in substations, switchgears, switchboards, motorcontrol centres and panel boards without doors : engraved lamacoid nameplates,black with 3 mm high white lettering.

(b) in panel boards with doors : directories mounted inside transparent plastic covers inmetal frames.

3 Wiring Identification:

(a) identify wiring with permanent indelible, identifying markings, either numbered orcoloured, heat shrinkable tube or ferrules, on both ends of phase conductors offeeders and branch circuit wiring.

(b) maintain phase sequence and colour coding throughout(c) colour code to standards above as specified elsewhere


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(d) use colour coded wires in communication cables, matched throughout system.

4 Conduit and Cable Identification:

(a) colour code conduits and metallic sheathed cables(b) code with plastic sleeve or paint end points where conduit or cable enters wall, ceiling

or floor and also at 15 m intervals along its length.(c) colours to be 25 mm wide prime colour and 20 mm wide auxiliary colour to standards

above(d) number code, per Circuit Schedule, all feeder and branch circuit cables at both

connection points and in manholes, handholes, pull-boxes and junction boxes withfibre or non-ferrous metal tags, fastened with non-ferrous wire.

5 Device Plates:

(a) for Device Plates of local toggle switches, toggle switch type motor starters, pilotlights and the like, whose junction is not readily apparent : plates to be engraved with 3mm high letters describing equipment controlled or indicated.

6 For Busbars:

(a) phase identification letters shall be stamped into the metal of the busbars of eachphase of the main buses in each substation, switchgear, switchboards, motor control

centre and panel board in addition to colour identification(b) Letters shall be visible without disassembling current carrying supporting elements.(c) busbars shall be sleeved for phase identification by using high temperature grade heat

shrinkable coloured PVC sleeving throughout its length. In no circumstances will anykind of wrapping tape be accepted on busbars.

7 For Doors:

(a) where switchboard rooms, cable chambers, metal screened spaces and the likecontain electric power cables, bus bars or equipment operating at voltages exceeding600 V : enamelled sheet metal, red on white, reading "Danger - High Voltage".

8 For Rooms:

(a) to switchboard rooms, electric closets, metal screened spaces assigned to electrical

equipment, and the like : enamelled sheet metal, red on white, reading "ElectricalEquipment Room - No Storage Permitted".

9 Languages:

(a) nameplates with directional, operational or warning labels shall be in Arabic andEnglish.

1.1.20 Segregation of Services

1 Electrical services shall be segregated as specified throughout the installation to obviate thefollowing;

(a) electrical interference from one circuit to another(b) a fault on one circuit affecting another

(c) unnecessary fire damage(d) difficulties in circuit identification(e) voltage limits for general safety(f) difficulties in removal and/or maintenance.

2 All raceways shall be kept clear of other services except where intentionally earthed orbonded. Generally, raceways shall be kept 150 mm away from and above hot water and 75mm away from other services.

3 Unless specifically indicated otherwise, normal, emergency, low voltage cables and wiringshall be segregated throughout the installation generally in the following manner:


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(a) armoured and sheathed cables: Where more than one tray has been specified or isnecessary to accommodate the number of cables on a run, where practical,segregation shall be achieved by dedicating each tray to either normal or emergencyservices. Where normal and emergency cables have to run together in trays, ductsor trenches, they shall be formed in two groups, one normal and one emergency

(b) insulated conductors: Insulated conductor circuits shall, where possible, besegregated throughout by enclosing in separate conduits, trunking or trunkingcompartments.

4 Fire Alarms:

(a) fire alarm cables shall be segregated from other services throughout and be eitherarmoured and sheathed cable, or insulated conductors enclosed in conduit ortrunking, as indicated on the drawings.

1.1.21 Electricity Supply

1 The Supply Authority will make available, at the incoming terminals of each Main Switchboard(Medium Voltage Panel) a 3 phase + Neutral, 4 wire, 415 V, 50 Hz supply of adequatecapacity and having the following tolerances:

(a) voltage ± 6 %

(b) frequency±

0.1 Hz (short term±

0.15 Hz for a duration of only a few seconds)2 Phase rotation of supply to BS 158.

3 Neutral: Solidly earthed at transformer location

4 Earthing system: TNS

5 Obtain fault level and fault duration time from the Supply Authority (QGEWC).

6 Obtain confirmation from the Supply Authority of the size and number of cables they willprovide to Main Switchboards. Allow for adequate and appropriate cable glands, lugs andboxes.

7 After inspection and approval of the contractor ’s installation, QGEWC will permit energisation

of the feeder cables to the installation.

8 QGEWC will only inspect the contractor's installation and permit energisation of the powersupply after receiving a written request to do so from the contractor.

9 The contractor will be responsible for any delay caused by omission to make the request ingood time.

10 The contractor shall provide a generator of adequate capacity to carry out all pre-commissioning tests. Per-commissioning tests may be carried out using mains electricity ifthis is available.

1.1.22 Polarity

1 The polarity of all apparatus used for the Works specified shall be arranged as follows whenapparatus is viewed from the front:

(a) for two pole apparatus the phase or “live” pole at the top (or left hand side) and the'“neutral or earthed” pole at the bottom (or right hand side). On plug and socket outletsthe polarity shall conform to BS 196, BS 546, or BS 1363 as appropriate

(b) for three or four pole apparatus the phases in order red, yellow, blue and neutralreading from top to bottom or left to right in the case of vertical and horizontal layoutsrespectively.


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2 All cables shall be so connected between main switchboards, distribution boards, plant andaccessories so that the correct sequence of phase colours is preserved throughout thesystem.

3 All cable cores shall be identified with phase colours. Where more than one phase isincorporated on a common system in one room then the live cores shall be red, yellow, blue,as appropriate, and fittings and switch accessories shall be permanently labelled andsegregated in accordance with I.E.E. Regulations.

1.1.23 Safety Interlocks

1 A complete system of interlocks and safety devices shall be provided as necessary for thesafe and continuous operation of the plant in order to provide for the following:

(a) safety of personnel engaged on operation and maintenance of the plant(b) correct sequence of operation of the plant during start up and shut down(c) safety of the plant when operating under normal or emergency conditions.

2 Interlocks shall be preventive and not corrective

3 The Contractor shall be responsible for the preparation of interlocking schemes for theapproval of the Engineer.

4 Locks for interlocking purposes shall be of the figure lock type.

5 No spare or master key shall be provided, unless specified.

6 Device items are to be arranged to ensure that there is no danger of interchange with existinglocks on other units.

1.1.24 Spare Parts

1 General:

(a) provide sufficient spare parts as follows. Submit to the Engineer a list of all spareparts to be required for a further two years operation from the date of issue of theMaintenance Certificate

(b) spare parts required include but not necessarily limited to those listed below, providedspecified in the Project Documentation or where quantities for each item or equipment

is recommended by the manufacturer(c) spare parts to be delivered to central stores.

2 Main Low Tension Boards:

(a) 2 % spare moulded case circuit breakers of all different frame sizes, but in any casenot less than 2 nos. circuit breaker of each size

(b) 5 % spare indicating lamps for each indicating lamp in the switchgear(c) one set of tools required for switchgear maintenance(d) provide complete spare parts as recommended by the manufacturer for different

sizes of ACB.

3 Switchboards, Motor Control Centres and Distribution Boards:

(a) 5 % spare combination magnetic motor starters(b) 5 % spare circuit breakers for each rating of each MCCB(c) 5 % spare HRC fuses for each rating(d) 5 % spare of load break switch (isolators) of each size(e) 5 % spare of current operated ELCB of each size

4 Disconnecting Switches:

(a) 5 % spare switch of each size.


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5 Circuit Accessories:

(a) plug fuses - furnish ten percent (10%) of the number of each size and type of fusesinstalled, but in any case not less than six fuses of each sizes

(b) wall switches - provide five percent (5%) of the number of each size and type of wallswitch installed

(c) socket outlets - provide five percent (5%) of the number of each size and type installed(d) lamps - provide five percent (5%) lamps of each size and type for indicating panels

and pilot lights installed for different systems.

6 Lighting Fixtures:

(a) for lighting fixtures provide the following spare parts:(i) 2 % of the total quantity of each type of lighting fixture. This quantity shall

not be less than one fixture of each type(ii) additional diffusers for 5 % of the total quantity of each type of lighting fixture

provided with acrylic, plastic or glass enclosures. Diffusers shall be identical tothose of the installed fixtures. This quantity shall not be less than two diffusersof each type

(iii) 10 % spare lamps of each wattage of different type(iv) 5 % of the total quantity of controlgear (ballast) of each type and size but in

no case less than (6) ballast of each size and type.

7 Emergency Generating Sets:

(a) complete itemised list of different spares to be included and priced by the tenderers.For emergency generator, furnish by the generator supplier to maintain it for two years.

8 The tenderer shall submit with his offer detail prices of the spare parts he is required to provideunder the Contract indicating the quantity and the unit rate of each item.

1.1.25 Protection of Excavation

1 The Contractor shall comply with all requirements of the Police Department for marking,lighting and protecting excavations. It is the responsibility of the Contractor to ascertain therequirements of Police Department and to comply fully with these requirements. No additionalpayments will be authorised under any circumstances for marking, lighting or protectingexcavations.

2 Where carriageway works and road crossings are performed the Contractor shall providesteel plates of sufficient size and quality to permit the safe passage of traffic and the plateshall be so placed (if necessary fixed) to permit reasonable traffic flow.

3 All doorways, gates and entrances shall be kept clear with full access. Where excavationsimpede pedestrian access, crossings boards shall be provided. Crossing boards shall be1250mm wide with a hand rail on both sides 1 metre high and guard rails on both sides atvehicular access to premises etc. Ducts will not be installed at entrances to premises unlessinstructed by the Engineer.

4 Materials excavated shall be placed so as to prevent nuisance or damage. Where this is notpossible, the material shall be removed from site and returned for backfilling on completion ofcable laying at the Contractor’s expense. In cases where the excavated material is not to be

used for backfilling trenches it must be removed from site on the same day as it is excavated.Surplus material shall only be disposed of at Government approved sites. At the time ofContract award the Contractor shall contact the Ministry of Municipal Affairs and Agricultureto ascertain the approved sites and route.

1.1.26 Supply of materials

1 Where materials are to be supplied by the Contractor, the following shall apply:

(a) Materials shall be ordered in accordance with the Specifications issued by QGEWC.


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(b) Specifications and details of the proposed supplier shall be submitted to QGEWCbefore a firm order being placed.

(c) On delivery of materials from outside of Qatar, QGEWC inspectors shall be given theopportunity to inspect the materials prior to their use.

1.1.27 Special Requirements

1 The Contractor shall consult the public utility authorities not less than one month before it is

proposed to commence work to ascertain whether any underground installations will beaffected by the proposed work, in which event the Contractor shall make all necessaryarrangements with the public utility authorities to safeguard the installation.

2 The Contractor shall give at least one week’s notice in writing to the public utility authorities ofthe dates upon which it is intended to operate plant or equipment or carry out any work forwhich permission has been given in writing by the public utility authorities: such operations ofwork shall only be carried out in the presence of the public utility authorities unless notice hasbeen obtained in writing from the public utility authorities that they do not require to bepresent.

3 The public utility authorities may require work to be executed on their installation during theperiod of the Contract: the Contractor shall afford all facilities to the public utility authorities ’ contractors or workmen until their diversion work is complete. The Contractor shall co

ordinate the work of the public utility authorities and his own activities and when necessaryshall amend his programme of working to suit all requirements of the department inconnection with their diversion work and shall keep the Engineer informed of allarrangements made.

4 The Contractor shall locate and mark with suitable posts all the public utility authoritiesunderground installations that are within the area of the Works and shall ensure that suchmarkers are maintained in their correct positions at all times; the Contractor shall advise thepublic utility authorities of any installation not found where shown on the Drawings, or foundbut not shown or found damaged or subsequently damaged.

END OF PART


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QCS 2007 Section 21 Part 2 MV Factory Built Assemblies (FBA’s) Page 1

Qatar General Organization for Standards and MetrologyQCS 2007, 3

rd Edition

2. MV FACTORY BUILT ASSEMBLIES (FBA’S)............................................... 2

2.1 GENERAL...................................................................................................... 2

2.1.1 Scope 2 2.1.2 General Reference 2

2.1.3

References 2

2.1.4 Submissions 3 2.1.5 Quality Assurance 3

2.2 PRODUCTS................................................................................................... 4

2.2.1 Cubicle Switchboards 4 2.2.2 Motor Control Centres 16 2.2.3 MCCB Panel Boards 19 2.2.4 Distribution Boards 20

2.3 INSTALLATION............................................................................................ 20

2.3.1 General 20

2.3.2

Earth Bonding 21


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2. MV FACTORY BUILT ASSEMBLIES (FBA’S)

2.1 GENERAL

2.1.1 Scope

1 This Part shall include all labour, materials and accessories for the complete performance ofall MV Cubicle Switchboards, Main Switchboards, Submain Switchboards, Motor ControlCentres, MCCB panel boards, distribution boards in accordance with the Specifications andDrawings.

2 Related Parts and Sections are as follows:

This SectionPart 1 General Provisions for Electrical InstallationPart 6 Cables and Small WiringPart 7 ConduitsPart 8 TrunkingPart 9 Cable TraysPart 16 Power factor correction capacitors

3 Factory built assemblies of switchgear and control gear (MCCs) shall be suitable for

operation under the ambient and service conditions specified. They shall comply with all localregulations and requirements. The contractor shall be responsible for making himself awareof any special conditions which apply to the installation.

4 The Contractor shall be responsible for ensuring that all details relating to the constructionand protection systems are fully compliant with the latest requirements of QGEWC andconstruction shall not commence until QGEWC approval has been obtained. The Contractorshall provided all protection relays, interlocks and devices deemed necessary by QGEWC.

2.1.2 General Reference

1 The work of this Part is integral with the whole of the Project Documentation and is notintended to be interpreted outside that context.

2 Co-ordinate the work with all other services affecting the work of this Part.

2.1.3 References

1 The following standards are referred to in this Section:

BS 88, BS EN 60127 Cartridge fusesBS 142 Electrical protective relaysBS 159, BS EN 60439-2 Busbar and connectionBS 7354, BS EN 60439, BS EN 6094 Electrical power switchgearBS 7626, IEC 185 Current transformersBS 4794, Pt. 2 IEC 337-2 Control devicesBS 37 Pt. 1 Electricity meters general

BS 89, IEC 51 Direct acting indicating electrical measuringinstrumentsBS 5685, IEC 521 Electric metersBS EN 60529, IEC 529 Degree of protection of enclosuresBS 4752, IEC 157-1, BS EN 60439 Switchgear and control-gearBS EN 60947-3, IEC 408 Air break switchesBS EN 60947-4 IEC-1 & 1A ContactorsBS 5472, BS EN 60439 Low voltage switchgear and control-gearBS 6231 PVC insulated cables for switchgearBS EN 60439, IEC 439 Factory built assemblies LV


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BS EN 60073 Basic and safety principles for man-machineinterface, marking and identification codingprinciples for indicators and actuators

2.1.4 Submissions

1 Shop Drawings: All submittals in accordance with Part 1:

(a) submit dimensional drawings of all the switchgears, switchboards and motor controlcentres, including sections and elevations, showing the following:(i) arrangement of all components, instruments, indication and dimensions of all

busbars(ii) positions and method of fixing cables and boxes(iii) location of terminal blocks(iv) single line diagram of the circuits showing the rating of all components, the

type and size of the incoming and outgoing feeders(v) schematic and elementary wiring diagrams, for each control unit, showing

numbered terminal points, numbered wires and numbered interconnections toother equipment and remote devices

(vi) connection wiring diagrams, for each control unit, showing numbered terminalpoints, numbered wires and numbered interconnections to other equipmentand remote devices

(vii) complete catalogue information for all components(viii) a complete list of parts, with prices, that would be necessary to maintain and/or

modify the equipment(ix) other relevant data.

2 Product Data:

(a) full specifications of the enclosures and the components of the switchgear,switchboards and motor control centres, with relevant sheets of manufacturer ’scatalogues

(b) type test certificates of all components and whole assembled MCCs from aninternationally recognised testing authority or from independent testing lab inaccordance with IEC 439

(c) confirmation that the switchgears, switchboards and motor control centres complywith the relevant specification as mentioned in this Section.

2.1.5 Quality Assurance

1 The switchgear manufacturer must have a previous record of satisfactory service in Qatar forat least 3 years.

2 All new and refurbished Motor Control Centres shall be subject to routine tests to detect faultsand workmanship in accordance with BSEN 60439-1 clause 8.3.1. Standard assembliesand/or products used within the assembly shall also be subject to tests at the manufacture’sworks who supplied the products. Routine tests shall include:

(a) the effectiveness of mechanical actuating elements, interlock, locks etc. shall bechecked. The conductors and cables shall be checked for proper laying and thedevices for proper mounting. A visual inspection is also necessary to ensure that theprescribed degree of protection, creepage and clearances are maintained.

(b) all termination types and connections especially screwed connections shall be checkedfor adequate contact.

(c) factory built assemblies such as motor control centres for pumping stations andtreatment plants, unit mounted stand alone control panels etc. shall be inspectedthoroughly and tested at the manufacturer's works to verify the electrical operation inaccordance with the control philosophy by simulating the site conditions.

(d) the manufacturer shall submit the process flow diagram together with cause andeffects for the assemblies involving complex control schemes and complicatedinterlock, sequence controls, etc.


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(e) the tests so conducted on the assembly at manufacturer's works shall be repeated asintegrated tests on site with all field devices and interfaces present.

(f) the manufacturer shall submit in advance, the testing procedure to the Engineer forapproval prior to conducting the tests.

(g) Motor Control Centres shall be subjected to dielectric tests as described in BSEN60439-1 clause 8.3.2. All electrical components of the assembly shall be connectedfor the test, excluding those designed for lower test voltage and currents e.g.measuring instruments.

(h) anti-interference capacitors installed between the live and exposed conductive partsshall be capable of withstanding the test voltage without being disconnected from thecircuit.

(i) the protective measures with regard to protection against direct and indirect contactshall be checked as per BSEN 60439-1 clause 8.3.3

(j) Motor Control Centres shall be Totally Type Tested to BSEN 60439-1 clause 8.2. ASTA/KEMA type test certificate together with test report including reports/terms under(k) shall be submitted to the Engineer for approval.

(k) following is a list of verifications and tests to be performed on a Totally Type Tested Assembly according to Table 7 clause 8.2 of BSEN 60439-1. A test report shall besubmitted to the Engineer(i) temperature rise limits(ii) dielectric properties(iii) short circuit withstand strength

(iv) effectiveness of protective circuit• effective connection between the exposed conductive parts of the

assembly and the protective circuits.

• short circuit withstand strength of the protective circuit(v) clearances and creepage distances(vi) mechanical operation

(vii) degree of protection

2.2 PRODUCTS

2.2.1 Cubicle Switchboards

1 General:

(a) M.V. cubicle switchboards shall be of indoor construction, purpose made, floorstanding, totally enclosed, cellular cubicle type, dust protected,vermin proof and of clean and modern appearance containing the main componentsshown on the Drawings and/or specified

(b) the switchboards shall be fabricated, assembled, wired, checked, tested andco-ordinated at the factory by one manufacturer using the same make for all internalswitchgear components and shall be constructed in accordance with BS EN 60439or IEC 439

(c) the switchboard shall be equipped with Air Circuit Breakers, moulded case circuitbreakers, relays, instruments, transformers, ancillary devices necessary for operationprotection or measurement purposes and Auto Transfer Switch with Manual by passarrangement as indicated on the Drawings

(d) the normal components, fittings and accessories required for safe and properoperation of switchgear shall be provided, whether specifically mentioned herein ornot

(e) to withstand thermal and mechanical stresses set up by short circuit conditionsin accordance with the fault through current of the feeding transformer. In generalfault breaking capacities for main switchboards shall be as stipulated in QGEWC regulations

(f) spare ways indicated on the Single Line Diagram shall be fully equipped(g) all FBA’s should have a manufacturers name plate indicating busbar rating, fault

current, year of manufacture, serial no., etc.(h) the MCCs shall be designed, manufactured and tested to IP54 in compliance with the

requirements of IEC 60529.


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(i) equipment such as Variable Frequency Drives (VFD), UPS and others with large wattloss, if specifically mentioned in the particular requirements to be included in the MCC,that require forced ventilation by employing external fan and louvers as recommendedby the manufacturer, the degree of protection (IP rating) shall be reduced to IP43 fromIP54.

(j) the MCCs shall be designed and type tested to withstand a fault current of 44 kA for 3seconds symmetrical. Additionally the MCCs shall be type tested for safe containmentof an internal arcing fault, which will check the capability of the steel structure towithstand the forces associated with the arc, and ensure safety and integrity of theassembly for continuous use. This is to establish that the enclosure of MCCs togetherwith internal partitions and/or barriers withstands the pressure and temperature arisingfrom internal arcing with short circuit current and thus provides protection for personsin front of or within the close proximity of the MCCs in the event of internal arcing.

(k) the test certificate must show that the neutral bar has been tested with the full faultcurrent and for the full time specified.

(l) separate test certificates for incoming sections will be acceptable.(m) the MCCs shall be designed and equipped with properly sized circuit breakers and/or

fused disconnect switches, having a minimum factor of safety of capacity 1.5 takinginto account the connected load and its diversity, with provision for selective short-circuit co-ordination so that faults are cleared without disturbing other circuits.

(n) the MCCs shall be designed for indoor installation except where specified for outdoorinstallation.

(o) the MCCs shall be designed to operate satisfactorily in an ambient air temperature of+50° C and RH exceeding 90%.

(p) unless otherwise specified temperature up to +70° C and RH up to 100% shall applyduring transport, storage and installation. Equipment subjected to these extremeservice conditions without being operated shall not suffer irreversible damage whenoperated under normal specified conditions.

(q) the altitude of the site installation shall not exceed 100 meters.(r) the MCCs shall normally be located indoors in service conditions as specified above.

However some parts of the MCCs such as sensors, field instruments and pilot devicesmay require installation in highly corrosive gaseous environments. Gases such ashydrogen sulfide and methane may adversely affect the functions of the componentsand devices. In such application environments, special measure shall be adopted toprevent corrosion and the subsequent rise in resistance leading to temporary orpermanent interruption in control or power circuits.

(s) the temperature rise in MCCs shall not be allowed to damage the components,connectors, wires, terminals etc. With the equipment in normal service condition, nolive part shall become subjected to high temperature causing overheating thatincreases the risk of internal arcing accidents.

(t) extreme care shall be taken while designing the MCCs to ensure external surfacetemperature is maintained within the specified limits.

(u) the clearances and creepage distances in the MCCs shall be based on ratedimpulse withstand voltage in accordance with BS EN 60439-1 to ensure that theequipment designed is capable of withstanding the specified voltage without failureunder specified test conditions.

(v) the equipped MCC must confirm to the clearance and creepage distances andwithstand voltages explicitly by taking into account the specified service conditions.

(w) the maximum height of assemblies shall be 2400 mm above the finished floor level.(x) site consideration including safety and maintenance shall be taken into account in the

design of assemblies. These considerations shall include:(i) clear floor space of at least 900 mm shall be provided in front of the MCC from

the free edge of the doors in the open position. Clear floor space of 900mm shallbe provided behind the MCC when the doors are in the open position if the MCCis less than 4000mm long. If the MCC is 4000mm or longer the space providedshall be 1200mm. The clear floor space behind the MCC is not required when atrue front access assembly is provided.

(ii) in order to provide an unobstructed exit route a clear path of not less than 900mm shall be provided at each end of the MCC.

(iii) provision of sufficient space to allow for doors to open fully without fouling otheritems of equipment or other open doors.


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(iv) limiting the size and weight of assembly sections to those imposed bytransportation, site access and permitted levels of site floor loading.

(v) clear floor space of at least 1000 mm shall be provided from the sides of allMCCs in order to allow possible future extension.

2 Construction:

(a) unless specified otherwise in the Project Documentation, main switchboards for

general purpose indoor uses shall be constructed to comply with the requirements ofBS EN 60439-1 (IEC 439) Form 4 Type 3 or Type 7 and conform with GAMBICA.

(b) switchboard shall be factory built, totally enclosed, and have provision for rearaccess. Size, rating arrangements shall be as indicated on the Drawings

(c) the switchboard shall consist of standard cubicles assembled together on continuousbase channels to form a rigid in line flush fronted free standing continuous switchboardassembly. For small installations where particularly specified, true front access MCCsmust be provided. For all other cases front and rear access MCCs must be provided.MCCs shall be constructed such that doors and covers are flush with one another andaligned to a common vertical plane; manufactured out of mild steel coated with AluZinc having the following thickness:Plinth/bed frame - 3.00 mmFrames - 2.00 mmCovers and Doors - 2.00 mm

Mounting plate - 3.00 mmGland Plate - 3.00 mm

(d) a separate cubicle section shall be provided for the main incoming circuit breakerand cable glands shall be provided for the incoming cables in accordance with theQGEWC regulations.

(e) each cubicle shall be divided into segregated busbar section and circuit section. Thecircuit section shall be further divided into segregated compartments for housing mainand emergency circuit breakers and other devices. Access to internal components ofany compartment must be feasible by isolating its particular switch. The hinged doorshall be mechanically interlocked with the switch in such a manner that the door canbe opened only in the ‘OFF’ position

(f) the switchboards shall be totally enclosed, all hinged doors, covers shall be gasketedto provide protection against dust

(g) cabinet shall have adequate means of lifting and shall be capable of being rolled or

moved into the installation position and bolted directly to the floor(h) the switchboards shall be provided with suitable cable glands to suit the type, size andnumber of cables as indicated on the Drawings. The cable glands or bracket whererequired shall be adequately mounted inside the switchboard. The switchboards shallbe provided with the proper cable fixing clamps and terminal lugs for incoming andoutgoing cables as well as earth bonding connections

(i) after fabrication, steel work shall be cleaned, zinc sprayed and stove enamelled withone prime coat, two under-coats and one finishing coat, the surface being rubbeddown after each coat

(j) the finish of all parts shall be entirely suitable for the climatic conditions on site.(k) the equipment shall be finished with at least two coats of undercoat and two coats of

high grade acrylic stove enamel or approved equivalent. Cubicle interiors shall becompletely painted white, however this is not essential for the rear of the door.

(l) any damage caused to the finish during transportation and erection shall be returned tothe manufacturer for repair if it cannot be perfectly repaired on site.

(m) The exterior shall be green to BS 4800, shade 14E53.(n) all plastic parts used within the assembly shall be of flame-retardant, self

extinguishing type and halogen free.(o) MCCs shall have internal separation by means of metallic or non-metallic partitions or

barriers.(p) all internal components within the compartment /cubicle shall be provided with the

degree of protections to IP 2X as minimum whereas the degree of Protection to IP4Xshall be provided to adjacent functional units preventing contact with live parts.


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(q) electrical continuity between the exposed conductive parts of MCCs and protectivecircuits of the installation shall be ensured to provide protection against indirect contactby using protective circuits.

(r) the protective circuits throughout the installation shall be so designed that it isimpossible to break the protective path with the removal of any component from theMCC.

(s) all outgoing circuit’s protective conductors shall have a separate terminal of adequatesize duly identified in accordance with the Identification Section explained elsewhere inQCS.

(t) MCCs must be designed by giving highest importance to accessibility especially whenin service/fully powered, allowing easy viewing for inspection and operation,replacement of fuses and extension of additional functional units etc.

(u) floor mounted assembles shall either be provided with an integral plinth or a separaterolled mild steel channel bed frame, at least 50 mm high. Fixing shall be by not lessthan four holding down bolts per assembly section, located around the periphery of thesection. The fixing shall not be visible from outside the section, but shall be readilyaccessible from within.

(v) fixings for wall and pole mounted enclosures shall be provided outside the enclosure.The back of the enclosure shall not be drilled to accept fixings.

(w) the type of cubicle construction shall be multi-compartment type unless specifiedotherwise.

(x) compartments containing switchfuses, starters, control sections, distribution boards,

busbars, downdroppers and similar equipment shall be fully segregated. There shall beno aperture large enough to admit a 1mm diameter wire between any two adjacentcompartments. Each cubicle/compartment shall have its own door.

(y) interconnecting cables between adjacent compartments shall not proceed directly fromone to the other but shall pass through a vertical wall into a cabling compartmentbefore re-entering. Holes for interconnecting cables shall be of the minimum sizenecessary. All such holes shall be filled with insulating grommets.

(z) all cubicles shall be provided with a means of ensuring that equipment can beadequately isolated for maintenance purposes without interrupting essential loadswhich may continue to operate whilst maintenance is being undertaken.

(aa) distribution sections shall be fully insulated to allow safe operation by non-engineeringpersonnel.

(bb) doors shall be adequately sized to accommodate readily and neatly all mountedequipment, open at least 120 degrees, be rigidly constructed, suitably braced and

provided with at least two substantial hinges which shall be captive when the door isclosed. Doors shall be provided with stays to prevent over opening.

(cc) each door shall be provided with non-rusting metalic ‘T’ type handles at least one of,which shall be lockable.

(dd) the doors shall be fixed to the frame by substantial single knuckle non-rusting type, orinternal concealed type hinges. Hinges shall be on the left hand side of the door.Hinges shall not be welded to either the door or frame. Substantial continuousstainless steel type hinges over the whole height of the door may be considered if themanufacturer can provide evidence of long continuous service of this type of hinge onhis product.

(ee) locking combinations shall be provided as specified. Three keys for each key typeshall be provided on individual key rings having a nametag showing identify details.

(ff) where the need of padlocking facilities is identified by the engineer/employer, thepadlocks shall be supplied and fitted.

(gg) equipment shall not be mounted on covers. Covers shall not weigh more than 30 kg,and any cover over 7.5 kg shall be provided with a means of supporting the lower edgewhen its securing bolts are being inserted or removed.

(hh) removable back covers shall be provided.(ii) each door shall be provided with an internal welded earthing stud, and shall be bonded

to the assembly main earth bar.(jj) every incomer, starter, feeder, etc. shall have an individual terminal/gland box. Control

compartments and small power and lighting distribution boards must also haveindependent gland boxes but these may be common to more than one circuit.


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(kk) terminal/gland boxes may be externally mounted on the rear of the MCC or internal.Terminal/gland boxes shall not inhibit access to or maintenance of any part of theMCC.

(ll) outgoing main and control cables shall be glanded at the compartment so as to ensurea full earth screen to each compartment and shall also be glanded at plinth level tomake the complete MCC vermin-proof. Compartment gland plates shall be a minimumof 300mm above the plinth level gland plate.

(mm) gasket material used for sealing panel doors and covers and for door mountedinstruments shall be of highest quality and should not be subject to deterioration bytemperature, UV, hydrogen sulphide and methane.

(nn) doors and covers giving access to potentially live conductors shall be provided withprominent warning labels, in English and Arabic.

(oo) doors on outdoor assemblies shall be retained in the open position by the provision ofadequately fixed stays.

(pp) each cubicle/compartment shall be provided with a removable steel componentsmounting plate located clear of the cubicle rear panel.

(qq) all components, other than door mounted, shall be located on the component mountingplate by bolting into tapped holes or by using self-tapping screws. Nuts used forsecuring components shall be captive.

(rr) rail type fixings may be used where appropriate. Components shall not be mounted onany other surface.

(ss) no components shall be located within the assembly at a height greater than 2000 mm

or less than 500 mm above finished floor level.(tt) it shall be possible to replace and maintain any component without first removing other

components.(uu) bolts and nuts for cover fixing shall be captive and provided with protective washers to

prevent damage to paintwork.(vv) unless specified otherwise control supplies shall be 110V a.c. derived from a

transformer within the control compartment or in a separate compartment, fused on itsprimary circuit. Neutral shall be earthed with a removable link. Individual compartmentsshall be fed through a fused tapping next to the main 110v bus adjacent to thetransformer. Proper fuse coordination to be achieved to avoid one section fault fromaffecting the other section. Transformer shall be rated for at least 150% of themaximum loading for long service life.

(ww) auxiliary supplies such as 24 V AC/DC, 240 V AC etc. are specified in the relevantindividual component’s specifications.

(xx) each compartment shall be provided with a separately fixed compartment heater rated110 Volts AC. Apart from those in motor starter compartments the heaters shall becontrolled by means of individual “OFF/AUTO” switches. Auto operation shall be bymeans of adjustable panel mounted humidistat covering the range of humidityenvisaged.

(yy) MCCs shall be designed for ready extension at each end.(zz) all terminals for outgoing connections shall be located at a low level in the

compartment adjacent to the cable gland trays. Adequate space shall be provided theinstallation and dressing of site cables. It should be noted that site cables arefrequently oversized to allow for high ambient temperatures and long cable routes.Direct termination on equipment such as Distribution Board Fuses or Miniature CircuitBreakers (MCB’s) shall not be permitted.

(aaa) all main switches shall be arranged such that a minimum distance of 700mm existsbetween the glandplate and the bottom of the circuit breaker or terminals, whichever is

the less.(bbb) all live terminals shall be fully shrouded by using high-grade high temperature material.(ccc) all cable entries shall be affected using brass cable glands to IP rating as specified.(ddd) all cable glands shall be provided with earth tags.(eee) cables shall enter assemblies through detachable steel or aluminum/brass (for single

core cables); gland plates fitted at least 200 mm above finished floor level.(fff) gland plates shall be rust proofed and provided with a welded and bonded earthing

stud, and adequately sized to accommodate present and known future cablingrequirements. Access to both sides of each gland plate when it is in position shall bepossible from within the assembly. Cables shall enter at the top or bottom ofassemblies as specified and/or as shown on the relevant drawings where applicable.


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(ggg) cableways shall be provided to ensure that apart from inter-connections no cablerouted to one cubicle shall pass through any other cubicle.

(hhh) for cable sizes 300mm2 and above insulated glands shall be fitted.

(iii) provision for accommodation of rising armored cables shall be provided with adequatecable supports and a form of cable entry via approved cable glands secured to a steelglanding plate.

(jjj) space shall be provided to accommodate cable glands of appropriate size for incomingand outgoing circuits. All gland plates and trays shall be adequately earthed.

(kkk) cable disconnecting links shall be provided where specified and shall be used formaintenance purposes only. The links shall be fitted to the bus bar risers immediatelybefore the cable terminations and shall be easily accessible. The links shall be labeled‘ISOLATING LINK’ and the circuit or cable reference shall be quoted.

(lll) within each assembly, all metal parts of equipment supplied, other than those formingpart of an electric circuit, shall be bonded to the earth bar. Metalwork may be used forthis purpose provided that earth continuity conductors are fitted at all joints and otherdiscontinuities and those connections to metal work are made using a welded or boltedstud.

(mmm) the following metal parts must be provided with equipotential bonding connected toan earth busbar system by using yellow/green earth cable of at least 6.0 mm square.(i) gland plates(ii) gland covers(iii) side sheets

(iv) top barriers(v) intermediate barriers(vi) top covers(vii) end covers(viii) rear Covers(ix) front covers(x) cable Boxes(xi) doors and bolted front covers(xii) horizontal busbar barriers.

(nnn) each compartment shall be provided with a smoke detector. In addition to this a heatsensitive cable shall be run throughout the MCC passing through each compartment.Both shall be connected to the fire alarm panel and shall additionally be arranged toopen the main supply circuit breaker and inhibit the start up of the standby generator.

3 Labels:

(a) provide identification on all equipment e.g. control panels, MCC, controllers, raceways,boxes and conductors, devices etc in accordance with BS 61346, BS 61666, BS 61175and BS 60445 standards or latest edition of other applicable standards to the approvalof the Engineer.

(b) all labels shall be permanent, and be machine generated. NO HANDWRITTEN ORNON-PERMANENT LABELS SHALL BE ALLOWED.

(c) prior to making any label or nameplate for the purpose of identification, submit adetailed schedule indicating nameplate size, lettering size, color, material and actualnameplate information for the Engineer's review and approval.

(d) all external labels, nameplates, operational and warning signs shall be provided inEnglish.

(e) material used in making the engraved labels shall be of highest quality suitable for theenvironmental and climatic conditions as specified in the relevant section.

(f) critical devices such as disconnect switches; service feeders and branch circuitprotective feeders shall be legibly labeled to indicate its purpose and point of origin.The legibility distance shall not be less than 2.0 meters.

(g) identification nameplates shall be provided in addition to the manufacturer's equipmentnameplates as required by NEMA, BS, IEC or UL.

(h) warning signs and instruction labels wherever needed shall be provided in accordancewith all applicable local regulations.

(i) the contractor shall clearly show locations and fixing arrangements of nameplates andlabels on layout drawings.

(j) the contractor shall comply with the following requirements for labels:


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(i) provide equipment identification labels for all electrical equipment including, butnot limited to switchgear, control panels, switchboards, transfer switches,disconnect switches, transformers, generators, power factor capacitors, fixedequipment, motor starters, MCCs etc.

(ii) provided sub-classification label for all emergency power system, junction boxesand pull boxes.

(iii) external labels: Clear Perspex back engraved, in black letters on whitebackgorund in English with chamfered edges fixed with stainless steel screwswith nuts and flat & lock washers. The letters should be filled in white and therear surface painted black.

(iv) internal labels: Multi-layered plastic to an approved design engraved in English,and fixed with stainless steel screws. Alternatively special purpose made DINrail may be used for fixing labels as approved by the engineer.

(v) all labels shall be screw or rivet fixed and adhesive labels shall not be permittedunder any circumstances.

(vi) internal components labels shall have circuit designations correlated with thedrawings.

(vii) labels shall not be attached to trunking covers or other readily removable items.(viii) electrical equipment enclosures, vaults, doors and fences shall be provided with

"DANGER KEEP OUT" warning sign, showing proper voltage.(ix) disconnect switches and emergency devices shall have "CAUTION" warning

signs as directed by the Engineer.

(x) fuse and MCB distribution boards shall be provided with internal, screw fixed,engraved circuit labels. Ink on paper, ink on plastic, printed paper, printedplastic, plastic film or any kind of adhesive labels shall not be permitted.

(xi) provide a main Title Label all for electrical distribution and all other controlequipment, panels etc.

(xii) provide a Function Label for door mounted components.(xiii) every internal component - Identification Label.(xiv) provide a Identification Label for Protective devices - ( e.g. fuse/mcb type,

rating).(xv) provide a Title Label for Communication equipment.(xvi) compartments with doors and covers not electrically interlocked to an isolator,

external label - “ DANGER, LIVE TERMINALS ” with flash and voltage in redletters on white background in Arabic and English.

(xvii) provide a function description Label for group of terminal blocks.

(xviii) letter size shall be to the approval of the Engineer

4 Switchboard Wiring:

(a) wiring shall generally be of the multi-stranded high temperature to minimum 105° Cflexible PVC insulated, 600/1000V single core stranded copper type cable to BS EN6231. Where it is proposed to use alternative high temperature, double insulated orother special cable or insulated flexible laminated bus bar this should be brought to theattention of the Engineer for his approval.

(b) wiring shall be supported in insulated cleats or cable trunking. Adhesive type cleats ormounts shall not be used unless augmented by screw fixings.

(c) busbar chambers shall not be used as trunking for small wiring.(d) wiring shall be neatly laid and run in limited compression insulated cleats, insulated

straps or, where more than ten wires follow the same route, in plastic slotted-sidedtrunking with clip-on covers. Where trunking is used, the effective overall cross-

sectional area of cables shall not be greater than 70% of the trunking cross sectionalarea.

(e) wiring to items of equipment mounted on hinged doors or subject to movement shallrun in plastic sleeving or flexible conduit, being securely anchored at both ends; leavingample slack to prevent wiring strain, arranged so that they are subject to torsion ratherthan bending.

(f) holes in steelwork through which cables pass shall be protected using grommets orbushes, suitable for the size of hole.

(g) cables used for control, extra low voltage and instrument signal transmission, likely tobe affected by interference, shall be screened and/or spaced from each other and from


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heavy current power cables. The separation distance shall ensure that the resultantelectrical noise is insufficient to cause any form of malfunction of associatedequipment or give false readings.

(h) a sufficient number of terminal connections including 15 % spare terminals shall beprovided for all control and instrument wiring.

(i) all wiring shall be identified at each end by means of glossy plastic ferrules showing thewire number as on the schematic diagrams. Ferrules shall be color coded, ‘Z’ type andindelibly marked.

(j) where single core cable is to be accommodated, a non-magnetic gland plate shall beprovided. For cable size 300 mm Sq. and above insulated glands shall be fitted.

(k) undrilled gland plates shall be provided for the reception of conduits and threadedglands. Boxes and glands shall be within the cubicles except where otherwiseapproved.

(l) single strand wire shall not be used. The minimum cross sectional area of the wireused shall be 1.0 mm

2 (multi strand flexible) for control circuit and 2.5 mm

2 for power

circuit. Both ends of every wire shall be fitted with a white cable marker as describedabove. Clip on type cable markers shall not be used.Color-coding shall be:Red - Red phaseYellow - Yellow phaseBlue - Blue phaseBlack - Neutral

Green and Yellow - Earth/Protective conductorsGrey - 110V a.cWhite - 60 D.CPurple -


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(x) no more than one conductor shall be connected to one side of a terminal. Whereseveral conductors are to be connected, shorting bars shall be provided acrossmultiple terminals. Outgoing cables shall be wired so that all assembly wiring isconnected to one side only.

(xi) the terminal numbers, voltage grouping and terminal block layout shallcorrespond precisely with wiring diagrams so that quick and accurateidentification of wiring can be made.

(xii) all terminals shall show the circuit wire number reference.(xiii) a separate dedicated telemetry/RTU section shall be provided in the MCC

cubicle equipped with all terminals duly wired and located in the side or on thetop of the compartment interior leaving maximum room for free issued fully wiredand tagged RTU complete with all associated hardware’s on a mounting plate.When a PLC control system is provided the PLC should be suitable for telemetrycommunication and shall be configured to communicate with the S